efi/gop: Fix memory leak in __gop_query32/64()

efi_graphics_output_protocol::query_mode() returns info in
callee-allocated memory which must be freed by the caller, which
we aren't doing.

We don't actually need to call query_mode() in order to obtain the
info for the current graphics mode, which is already there in
gop->mode->info, so just access it directly in the setup_gop32/64()
functions.

Also nothing uses the size of the info structure, so don't update the
passed-in size (which is the size of the gop_handle table in bytes)
unnecessarily.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191206165542.31469-5-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/drivers/firmware/efi/libstub/gop.c b/drivers/firmware/efi/libstub/gop.c
index 69b2b019a1d02de26d8bb1a997e02702f884f4b8..b7bf1e993b8bb4d9c32596bb70835cbff98f819b 100644 (file)
--- a/drivers/firmware/efi/libstub/gop.c
+++ b/drivers/firmware/efi/libstub/gop.c
@@ -83,30 +83,6 @@ setup_pixel_info(struct screen_info *si, u32 pixels_per_scan_line,
        }
 }
 
-static efi_status_t
-__gop_query32(efi_system_table_t *sys_table_arg,
-             struct efi_graphics_output_protocol_32 *gop32,
-             struct efi_graphics_output_mode_info **info,
-             unsigned long *size, u64 *fb_base)
-{
-       struct efi_graphics_output_protocol_mode_32 *mode;
-       efi_graphics_output_protocol_query_mode query_mode;
-       efi_status_t status;
-       unsigned long m;
-
-       m = gop32->mode;
-       mode = (struct efi_graphics_output_protocol_mode_32 *)m;
-       query_mode = (void *)(unsigned long)gop32->query_mode;
-
-       status = __efi_call_early(query_mode, (void *)gop32, mode->mode, size,
-                                 info);
-       if (status != EFI_SUCCESS)
-               return status;
-
-       *fb_base = mode->frame_buffer_base;
-       return status;
-}
-
 static efi_status_t
 setup_gop32(efi_system_table_t *sys_table_arg, struct screen_info *si,
             efi_guid_t *proto, unsigned long size, void **gop_handle)
@@ -128,6 +104,7 @@ setup_gop32(efi_system_table_t *sys_table_arg, struct screen_info *si,
 
        nr_gops = size / sizeof(u32);
        for (i = 0; i < nr_gops; i++) {
+               struct efi_graphics_output_protocol_mode_32 *mode;
                struct efi_graphics_output_mode_info *info = NULL;
                efi_guid_t conout_proto = EFI_CONSOLE_OUT_DEVICE_GUID;
                bool conout_found = false;
@@ -145,9 +122,11 @@ setup_gop32(efi_system_table_t *sys_table_arg, struct screen_info *si,
                if (status == EFI_SUCCESS)
                        conout_found = true;
 
-               status = __gop_query32(sys_table_arg, gop32, &info, &size,
-                                      &current_fb_base);
-               if (status == EFI_SUCCESS && (!first_gop || conout_found) &&
+               mode = (void *)(unsigned long)gop32->mode;
+               info = (void *)(unsigned long)mode->info;
+               current_fb_base = mode->frame_buffer_base;
+
+               if ((!first_gop || conout_found) &&
                    info->pixel_format != PIXEL_BLT_ONLY) {
                        /*
                         * Systems that use the UEFI Console Splitter may
@@ -201,30 +180,6 @@ setup_gop32(efi_system_table_t *sys_table_arg, struct screen_info *si,
        return EFI_SUCCESS;
 }
 
-static efi_status_t
-__gop_query64(efi_system_table_t *sys_table_arg,
-             struct efi_graphics_output_protocol_64 *gop64,
-             struct efi_graphics_output_mode_info **info,
-             unsigned long *size, u64 *fb_base)
-{
-       struct efi_graphics_output_protocol_mode_64 *mode;
-       efi_graphics_output_protocol_query_mode query_mode;
-       efi_status_t status;
-       unsigned long m;
-
-       m = gop64->mode;
-       mode = (struct efi_graphics_output_protocol_mode_64 *)m;
-       query_mode = (void *)(unsigned long)gop64->query_mode;
-
-       status = __efi_call_early(query_mode, (void *)gop64, mode->mode, size,
-                                 info);
-       if (status != EFI_SUCCESS)
-               return status;
-
-       *fb_base = mode->frame_buffer_base;
-       return status;
-}
-
 static efi_status_t
 setup_gop64(efi_system_table_t *sys_table_arg, struct screen_info *si,
            efi_guid_t *proto, unsigned long size, void **gop_handle)
@@ -246,6 +201,7 @@ setup_gop64(efi_system_table_t *sys_table_arg, struct screen_info *si,
 
        nr_gops = size / sizeof(u64);
        for (i = 0; i < nr_gops; i++) {
+               struct efi_graphics_output_protocol_mode_64 *mode;
                struct efi_graphics_output_mode_info *info = NULL;
                efi_guid_t conout_proto = EFI_CONSOLE_OUT_DEVICE_GUID;
                bool conout_found = false;
@@ -263,9 +219,11 @@ setup_gop64(efi_system_table_t *sys_table_arg, struct screen_info *si,
                if (status == EFI_SUCCESS)
                        conout_found = true;
 
-               status = __gop_query64(sys_table_arg, gop64, &info, &size,
-                                      &current_fb_base);
-               if (status == EFI_SUCCESS && (!first_gop || conout_found) &&
+               mode = (void *)(unsigned long)gop64->mode;
+               info = (void *)(unsigned long)mode->info;
+               current_fb_base = mode->frame_buffer_base;
+
+               if ((!first_gop || conout_found) &&
                    info->pixel_format != PIXEL_BLT_ONLY) {
                        /*
                         * Systems that use the UEFI Console Splitter may